1. Field of the Invention
The present invention relates to a control apparatus for a hybrid vehicle which can travel by the driving force of at least one of an engine and a propulsion motor.
2. Description of Related Art
Heretofore, for a hybrid vehicle which can travel by the driving force of at least one of an engine and a propulsion motor there exists one in which there is provided a motor electronic control unit to control the propulsion motor, and an engine electronic control unit to control the engine, and a DBW (Drive By Wire) control technique is adopted to electrically control the opening of the engine throttle by means of the engine electronic control unit which controls a throttle actuator. (For example, see Japanese Unexamined Patent Application, First Publication No. Hei 10-4608).
On the other hand, there exists a vehicle provided with a generator which is driven by engine rotation to generate power and charge a storage device (battery) which supplies power to an electrical load installed in the vehicle, in which there is provided an engine rotation speed fluctuation prevention device, which is able to prevent an increases in engine rotation speed in cases where an amount of power generated by the generator is set to zero so as to not overcharge the storage device, and in cases where an increase in engine rotation speed is caused as a result of fluctuations in the engine load. This apparatus detects a decreasing change in the generator current flowing from the generator to the storage device, and in the case where the decreasing change is low, effects operation of an intake air quantity correction device which corrects the intake air quantity of the engine, and in the case where the decreasing change is moderate, effects operation of an ignition control section which corrects the ignition, and in the case where the decreasing change is high, effects operation of a fuel cut which instructs fuel injection to cease. (For example, Japanese Unexamined Patent Application, First Publication No. Hei 09-14009.)
However, with the conventional technique, such as the above, in which the current value flowing to the storage device is detected by a current sensor, and control is performed by controlling the intake air amount to the engine, the engine ignition, and the engine fuel injection amount, and the like, in order to prevent fluctuations in engine rotation speed caused by fluctuations in the engine load, there has been a problem of the possibility of charging being more than is necessary, in the case where the engine rotation speed increases abruptly due to abrupt operation of the accelerator and as a result storage current has flowed from the generator and the propulsion motor to the storage device, for example in a storage device such as a battery where the lower the temperature, the greater the internal resistance.